Counterfeiting is baaaaad, right? Definitely naughty.

But astronomers have decided that it’s a Good Thing, and are now creating not one but many fake Universes.

They call them simulations rather than fakes, but it amounts to the same thing.

Basically they take everything we know about what we see in the sky—both things that have been seen directly, and our theories about the cosmos—and create a replica Universe in a computer.

Then they observe it with a simulated telescope.

That sounds kind of kooky, but it’s actually quite useful. In fact, it’s essential now for planning projects that you’ll be doing with complex high-performance telescopes such as CSIRO’s Australian SKA Pathfinder.

First off, when you use your simulated telescope, you can build in the kind of limitations on performance that real telescopes have. Things like calibration errors, for example.

Second, it helps you to interpret your results. When you finally get your data from your brand new real telescope, you can compare it with what your dummy Universe and simulated telescope produced. If the two sets of data are different then you know your original understanding of some process—say, how galaxies evolve over time—wasn’t quite right.

And third, comparing the real data with the simulation can show up things that are completely unexpected. The Universe may be telling you something new.

People have been talking for years about creating simulated Universes, but it’s only in the last year or so that it has really taken off.

The University of Western Australia held a meeting last week for people who are into this.

CSIRO’s Dr Ray Norris was one of them.

He’s planning a humungous survey called EMU (Evolutionary Map of the Universe), to be done with the ASKAP telescope.

Simulations are essential, he says, if EMU’s going to fly.

Below, the Millenium Simulation by the Virgo Consortium at the Max Planck Institute for Astrophysics.  Enjoy!